从0搭建一个Springboot+vue前后端分离项目(六)后台编写配置类与接口

从0搭建一个Springboot+vue前后端分离项目(六)后台编写配置类与接口

新建一个包,里面放入一些常用的配置类

引入mybatis-plus包与插件

引入包

前往官网查看

https://baomidou.com/pages/226c21/#%E5%88%9D%E5%A7%8B%E5%8C%96%E5%B7%A5%E7%A8%8B

    com.baomidou
    mybatis-plus-boot-starter
    3.4.3.4

MybatisPlusConfig----MybatisPlus配置文件

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@MapperScan("com.example.demo.mapper")
public class MybatisPlusConfig {
    
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.H2));
        return interceptor;
    }
}

配置result包装返回与前台交互数据对象

code 代表成功或者失败;
msg即返回的信息

package com.example.demo.common;
//T是范型
public class Result {
    private  String code;
    private  String msg;
    private T data;

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

    public Result(){

    }
    public Result(T data){
        this.data = data;
    }
    public static Result success(){
        Result result = new Result<>();
        result.setCode("0");
        result.setMsg("成功");
        return result;
    }
    //返回一个数据
    public static  Result success(T data) {
        Result result = new Result<>(data);
        result.setCode("0");
        result.setMsg("成功");
        return result;
    }

    //错误返回
    public static Result error(String code,String msg){
        Result result = new Result();
        result.setCode(code);
        result.setMsg(msg);
        return result;
    }
}

编写用户接口

新建一个包entity实体类

建一个java对象与数据库进行一 一对应

package com.example.demo.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

//与数据库的表名一一对应
@TableName("user")
//使用lombok插件简化快速写代码
@Data
public class User {
    //定义自增
    @TableId(type = IdType.AUTO)
    private Integer id;
    private String username;
    private Integer age;
    private String  sex;
    private String address;
    private String password;

}

编写用户接口UserControlller

新建一个包Controller

package com.example.demo.controller;

import com.example.demo.common.Result;
import com.example.demo.entity.User;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

//定义返回json数据
@RestController
//定义路由
@RequestMapping("/user")
public class UserController {
    //定义post接口
    @PostMapping
    //前端网页的新增用户接口,@RequestBody作用是使前台传来的json格式的代码转化为java对象
    public Result save(@RequestBody User user) {

    }

}

拿到user数据之后就可以把它插入到数据库当中,编写mapper部分

创建一个UserMapper接口类

前往mybatis-plus官网参考

https://baomidou.com/pages/49cc81/#mapper-crud-%E6%8E%A5%E5%8F%A3

继承baseMapper 就可以实现一些数据库单表的增删改查

package com.example.demo.mapper;

import com.baomidou.mybatisplus.core.mapper.baseMapper;
import com.example.demo.entity.User;

public interface UserMapper extends baseMapper {
}

最后完善一下UserConler接口

package com.example.demo.controller;

import com.example.demo.common.Result;
import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

//定义返回json数据
@RestController
//定义路由
@RequestMapping("/user")
public class UserController {
    //将mapper引入
    @Resource
    UserMapper userMapper;
    //定义post接口
    @PostMapping
    //前端网页的新增用户接口,@RequestBody作用是使前台传来的json格式的代码转化为java对象
    //泛型表示任何一种类型
    public Result save(@RequestBody User user) {
        userMapper.insert(user);
        return  Result.success();
    }

}